The overall goal of this project is to commercially produce ursodeoxycholic acid (ursodiol) from waste products (turkey bile) of the poultry industry by either a one-step microbial transformation process or by a chemical epimerization of chendiol to ursodiol. Ursodiol is medically used to dissolve gallstones. Ursodiol is very expensive ($800-$2000/kg) and only produced by companies outside the USA. The objective of this Phase I proposal is to demonstrate the technical feasibility of converting the chenodeoxycholic acid (chenodiol), found in turkey bile, to ursodiol in > 80% yields. The objective of the subsequent Phase II proposal is to scale- up the most viable process via pilot-plant to commercial quantities. The specific aims of this Phase I proposal are to: 1. Screen known aerobic and anaerobic bacteria for their ability to convert chenodiol to ursodiol. 2. Concurrently, determine the feasibility of converting chenodiol to ursodiol by an improved chemical epimerization pathway. 3. Identify optimal conditions such as pH, cofactors, metal ions, etc. for the biotransformation of chenodiol (from turkey bile) to ursodiol. 4. Isolate ursodiol from the culture media by filtration through a Sep-Pack column. Recover ursodiol from the Sep-Pack column by a solvent wash. Determine efficiency of the microbial vs. the chemical process.